From 484ffb193712ba28318a8e8c64c35f2d35ebcbc8 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Thu, 15 Jun 2023 22:15:11 +0200 Subject: [PATCH] drm: bridge: samsung-dsim: Drain command transfer FIFO before transfer [ Upstream commit 14806c6415820b1c4bc317655c40784d050a2edb ] Wait until the command transfer FIFO is empty before loading in the next command. The previous behavior where the code waited until command transfer FIFO was not full suffered from transfer corruption, where the last command in the FIFO could be overwritten in case the FIFO indicates not full, but also does not have enough space to store another transfer yet. Signed-off-by: Marek Vasut Reviewed-by: Jagan Teki Tested-by: Jagan Teki # imx8mm-icore Link: https://patchwork.freedesktop.org/patch/msgid/20230615201511.565923-1-marex@denx.de Signed-off-by: Sasha Levin --- drivers/gpu/drm/bridge/samsung-dsim.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c index 73ec60757dbcb..9e253af69c7a1 100644 --- a/drivers/gpu/drm/bridge/samsung-dsim.c +++ b/drivers/gpu/drm/bridge/samsung-dsim.c @@ -1009,7 +1009,7 @@ static int samsung_dsim_wait_for_hdr_fifo(struct samsung_dsim *dsi) do { u32 reg = samsung_dsim_read(dsi, DSIM_FIFOCTRL_REG); - if (!(reg & DSIM_SFR_HEADER_FULL)) + if (reg & DSIM_SFR_HEADER_EMPTY) return 0; if (!cond_resched())